Timers



12, 1958 J. J. EVERARD 2,847,525

TIMERS Filed Nov. 2, 195a INVENTOR. JOSEPH J. EVERARD.

ATTORNEY United States Patent TIMERS Joseph J. Everard, Two Rivers,Wis., assignor to Paragon Electric Company, Two Rivers, Wis.

Application November 2, 1956, Serial No. 620,038

2 Claims (Cl. 200-38) This invention relates to timers. In timerconstruction as heretofore made, such for example, as interval timers,it is the usual practice to provide two blades or leaves which projectfrom a support and which have contacts. One of the blades rests on a camand constitutes a cam follower and has a projecting portion which dropsinto a notch cut in the cam. The cam is usually known as a jump typecam. It is driven by a synchronous motor through suitable reductiongearing, and the cam itself is manually set for the desired interval oftime. When this interval has elapsed the projecting portion of one ofthe blades, the cam follower blade, drops into the notch of the cam andopens the contacts.

It is the usual practice to make these blades of spring strip stock, andit has been found that where the blades are supported merely at theirends that it takes very accurate adjustment to insure the correctworking of the device. For example, if the blade opposite the camoperated blade is not adjusted properly, it may be so far out that thecam operated blade can never engage it. On the other hand, if it ispositioned too far in, through an error in adjustment, the contacts willnever open. Further than this, even if it is approximately correctlyadjusted, there is a tendency for the blade opposite the cam followingblade to vibrate and perhaps cause chattering of the contacts.

Various attempts have been made to remedy these defects. The principalone consists in providing a pin which extends outwardly fi'om asupporting plate, and which engages the blade opposite the cam followerblade when the contacts open, thus preventing the cam follower bladefrom moving inwardly beyond the desired position and maintainingcontact.

This invention is designed to overcome the above noted defects andobjects of this invention are to provide a timer construction in whichthe cam follower blade has a projecting portion that drops into a notchwhen the cam is in proper position, and in which the blade opposite thecam follower blade has a projecting end portion that is approximately atright angles to the main body of the blade and rests upon the camitself, when the cam has opened the contacts, to thus provide a stop forthe blade opposite the cam follower blade, and to prevent chattering ofthe contacts, and also to insure correct operation of the timer.

Further objects are to dispense wholly with any projecting pin or stopfor engagement with the blade opposite the cam follower blade, so thatall that is necessary is to provide the two blades and eliminate thestop entirely, with one of the blades arranged to rest upon the camitself when the contacts are open, both of the blades being biasedtowards the cam.

An embodiment of the invention is shown in the accompanying drawings inwhich:

Figure 1 is a face view of the device with the cover and associatedparts removed, the contacts being shown in closed position, and the cambeing set for the desired interval of time.

2,847,525 Patented Aug. 12, 1958 Figure 2 is a view similar to Figure 1showing the contacts in open position after the lapse of the interval oftime hereinabove mentioned.

Figure 3 is a sideelevation with parts broken away and parts in section.

Figure 4 is a sectional detail through the cam and the adjacent portionsof the device.

Figure 5 is a wiring diagram.

Referring to the drawings it will be seen that a synchronous motor hasbeen indicated by the reference character 1, and is carried rearwardlyof the plate 2. This motor, through reduction gearing, part of which isshown and indicated generally by the reference character 3, drives themain gear 4. The main gear in turn drives the cam 5.

The construction illustrated is what is commonly known as a jump typecam. The cam 5 rests or bears against the shouldered portion of adriving member 6, and fits over the hub 7 of such member and is drivenby this member. The driving member 6 is interposed be tween the cam 5and the main driving gear 4, and constitutes a slip joint or slipconnection between the driving gear 4 and the cam 5. A spring 8 bearsagainst the hub portion 7 of the driving member 6 and holds it infrictional engagement with the main gear 4. A shaft 9 extends throughthe cam and driver or driving member 6 and main gear 4, and has a tightfit with, or is otherwise secured to, the driving member 6 so that itwill move the driving member 6 and the cam 5 whenever the shaft 9 ismanually rotated.

For manual adjustment the hand knob 10 is secured to the extendedportion of the shaft 9 and is provided with a pointer 11 to indicate ona scale, not shown, formed on the cover plate 12, the interval of timefor which the device is set.

Fingers or contact members are indicated by the reference characters 13and 14. The contact member or finger 13 is providedwith a folded andprojecting portion 15 which is adapted to fit into or drop into a notch16 formed in the cam 5. The cam itself is preferably formed ofinsulating material.

Both of the contact fingers are of spring strip stock, and are providedwith contacts 17 and 18, as may be seen from Figures 1 and 2.

Both of the spring fingers or contact fingers 13 and 14 are biasedtowards the cam, or to the right as viewed in Figures 1 and 2. Thecontact finger 14 is provided with an extension 19 which extends overthe outer end of the contact finger or leaf 13, and is provided with arounded or upturned end 20 which rides upon or bears upon the circularportion or periphery of the cam 5 when the contacts are in open positionas shown in Figure 2.

The drive is through a pin 21 carried by the driving member 6 andprojecting outwardly through a short slot or arcuate opening 22 formedin the cam 5. This construction is old and forms no part of theinvention. It is provided so as to insure a quick break and completeopening of the contacts. For example, as seen in Figure 1, when the pin21 is driven by the synchronous motor in a counterclockwise direction itengages one end of the slot 22, and drives the cam 5. However, when theprojecting portion 15 of the finger 13 snaps into the notch 16 of thecam it does so with a quick motion and moves the cam 5 a slight amountin a counterclockwise direction. This provides a quick break.

Referring to the wiring diagram shown in Figure 5 it will be seen thatthe contact members 13 and 14 of the cam operated switch are connectedin series with the load 23 and the driving motor 1, the driving motorand the load being connected in parallel. The purpose of thisarrangement is to stop the motor when the load circuit is opened.

In using the device the operator merely sets the cam through the mediumof the hand knob 10, as shown in Figure l, to thus close the circuit andallow themotor to drive the cam. This also closes the supply circuit tothe load. When the interval of'time has elapsed for which the cam hasbeen set, the camf ollower blade or finger 13 moves to the rightas'viewed in Figure 2, and moves away from the other finger or blade 14,and thus opens the circuit. The finger 14 cannot follow the finger 13,except for a very slight distance, as its projecting portion 19immediately engages the rounded or circular portion of the cam 5 andthus arrests further motionof the blade 14.

It will be seen that this invention eliminates the use of a stop or apin for preventing vibration of the blade 14 on the one hand, and alsofor preventing the blade 14 from following the blade 13 over beyond thedesired position. Instead this invention provides a very simple meanswhereby the only requirement is the provision of extension 19 of theblade 14 which rests directly on the cam when the contacts are open asshown in Figure 2, thus eliminating any additional construction orcomplication.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

I claim:

1. An interval timer comprising a switch construction including a camhaving a circular portion provided with a notch, said cam being circularthroughout except for said notch, motor means for driving said cam, apair of spring blades biased towards said cam and supported adjacent oneend and having outwardly projecting free ends and having cooperatingcontacts, the free end of one of said blades having a portion adapted toenter the notch of said cam, the other of said blades constituting acooperating blade and having a portion bent angularly with referencetothe body portion of such blade and resting directly upon the circularportion of said cam when the cam follower blade is within the notch ofsaid cam, whereby motion of the cooperating blade towards the camfollower blade is limited by the direct engagement of the angula-rlybent portion of said cooperating blade with the circular portion of saidcam.

2. An interval timer comprising a switch construction including a camhaving a peripheral portion provided with a depressed portion, saidmotor means being connected in series with said switch constructionmotor means for driving said cam, a pair of spring blades secured at oneend and having free ends adjacent the peripheral portion of said cam andbiased toward said cam, one of said blades constituting a cam followerblade and having a part adapted to engage the depressed portion of saidcam, the other of said blades constituting a cooperatingblade and havinga portion bent angularly with reference to the body portion of theblade, the angularly bent portion of said cooperating blade restingdirectly upon the peripheral portion of said cam when said cam followerblade has moved away from the cooperating blade, whereby the emotionbetween said cam and the angularly bent portion of the cooperating bladelimits the motion of the cooperating blade toward the cam followerblade.

References Cited in the file of this patent UNITED'STATES PATENTSSchwarzenbach et a1, Dec. 3,

